MIAMI — There’s been a changing of the guard at second base for the A’s, manager Bob Melvin confirmed Saturday.

When Alberto Callaspo was once again the starter at second over Eric Sogard Saturday, the question was put to the manager with Callaspo playing against a right-handed starting pitcher for the sixth time in seven chances.

“He’s made his own opportunity,” Melvin said of Callaspo, who was 8-for-11 after coming back from a three-day paternity leave.

Callaspo has leveled off some since (5-for-24) then, but playing regularly has shown Melvin that Callaspo has the defensive chops for second base. He had not played in the middle of the infield for a few years, instead playing third base for the Los Angeles Angels until being traded to the A’s last season.

“His defense looks a lot better,” Melvin said. “A guy who had played some middle infield almost exclusively earlier in his career seems like he’s getting acclimated to it again.”

Sogard was the starter against right-handed pitchers all last year and most of this season.

“It’s obvious that Callaspo has been hitting a lot lately,” said Sogard, who has only three hits in his last 23 at-bats (.130), lowering his overall average to .194. “(Melvin) has talked to me about it. He’s going to ride whoever the hot hand is.

“And I just have to remember that I haven’t had a hot streak yet. But as long as we’re winning, it’s OK.”

“These things flip around, just like how he took control of the job,” Melvin said of Sogard. “So it’s all about performance. If someone is doing well, we’re going to be more apt to play them. He understands that.”

Miami right fielder Giancarlo Stanton led off the seventh inning Friday with a single to right. The Marlins didn’t score in the inning, so it became just another mark in the scoreboard.

Not in the Oakland clubhouse, however, where they were still talking about Stanton’s bullet off Ryan Cook before the game on Saturday. Cook threw about as nasty a fastball as he could, low and on the outsider corner, and Stanton crushed it.

“I was just talking about it with Sean Doolittle,” Cook said. “I am not a guy who can paint the corners all the time. But I’d just thrown Stanton two of the best fastballs I’ve thrown in a long time, if ever. I’m thinking if I come back with that pitch, he’ll either look at it or swing through it.”

Instead, Cook’s jaw dropped when he came back with a pitch “just where I wanted it,” and Stanton mauled it.

“I was thoroughly impressed,” Cook said. “When I let that pitch go, I knew it was just what I wanted. And he handled it.”

Derek Norris said he was feeling better after coming out of Friday’s game with back spasms, but that might not be enough to get him back in the lineup immediately.

The A’s had been hoping that with a day off Saturday, Norris might be able to catch the series finale Sunday with the Marlins throwing lefty Andrew Heaney. Melvin’s not willing to commit to that, however, not after watching Norris move around.

Disabled first baseman Kyle Blanks (left calf strain) hit in the cage Friday and played catch out to 105 feet but has not done any running yet. It’s not clear if he’ll be ready when his 15 days on the disabled list are up on July 8.

A’s shortstop Jed Lowrie was in a 7-for-66 skid when he hit a sinking liner to right in the first inning Friday. Right fielder Stanton, all 6-foot-6 of him, made a good charge on the ball, and Lowrie was fearing the worst.

The ball fell in, and Lowrie would go on to get another hit later in the game.

“I was like, ‘are you kidding me?”’ Lowrie said. “That would have been a tough one.”

Toxins released by the algae have poisoned dolphins, manatees, tons of fish and even contributed to the death of a 26-foot-long whale shark. The deluge of dead and rotting wildlife strewn across beaches has threatened to upturn the vital Florida tourist season